Hebrews 5:3

By reason hereof. Or “on account of this,” that is, on account of the fact that he himself was beset with infirmity. He had the same propensities toward sin as had his people, and the ancient ceremonial system required him to offer sacrifice for his personal sins.

Ought. Gr. opheild, “to be obligated.” The obligation was based on the requirements of the ceremonial law (see Lev. 16:6; cf. ch. 4:3). The fact that the high priest was required to offer sacrifices for his own sins would lead him to have compassion on the people. How could he blame others when he himself committed the same, or perhaps worse, wrongs? He needed to maintain a humble attitude, and regard with deep compassion those who failed. As a man considers his own weaknesses, he is not likely to condemn others mercilessly. Compare Gal. 6:1.

For the people. The reference is probably to the Day of Atonement, when the high priest made “an atonement for the children of Israel” (Lev. 16:34).

For himself. See above under “ought.”